Furnace construction



Nov. 12,1935. E LWATSQN HAL 2,020,862

FURNACE CONSTRUCTION Filed Nov. 19, 1954 2 SheetS-Sheefl 1 M v |NvENToR6' ATTORNEYS' Nov. 12, 1935.

E. L. WATSON ET AL FURNACE CONSTRUCTION y Filed Nov. 19, 1934 2 Sheets-Sheet 2 INVENTORB 1 MARGARET f. WA T60/Y ATTQRN EYS ateni;- Nov. 1.9351l zsztssz PATENT1 @Fries- FUBNACE CUNSVTRUCTION Earnest L. Watson and Margaret E. Watson,

4 Claims.

This invention relates generally to furnaces and refers morefparticularly to the combustion chambers of warm air furnaces.

Qne of the essential objects of the invention is to form a combustion chamber in such a way from lighter gauge metal that the heating area thereof in direct contact with the fire can be doubled without adding weight thereto. f

Another object is tov provide a combustion chamber wherein the formation referred to adds materially to the strength and rigidity of the structure and effectively prevents it from warping or twisting out of shape while in use.

Another object is to provide a combustion chamber embodying the foregoing and comprising several sections whichare separately formed but rigidly united in superposed relation.

Another object is to provide a combustion chamber wherein the sections just mentioned difvfer in diameter but have the same surface area per unit of height.

Another object is to provide a combustion chamber wherein. the formation previously mentioned cooperates with the fire brick lining of the ilre box portion of the chamber to form ducts for the passage of air upwardly from suitable openings in communication with the ash pit of the furnace.

Another object is to provide a combustion chamber wherein the openings just mentioned are formed in a ring which is rigid with the ash pit walls and forms a common support for the combustion chamber and fire brick lining.

Other objects, advantages and novel detalls of construction of ythis invention will be made more apparent as this description proceeds, es-

pecially when considered in connection with the accompanying drawings, wherein:

Figure 1 is a vertical sectional view through a furnace embodying our invention;

Figure 2 is an enlarged fragmentary perspective view thereof with parts broken away and in section;

Figure 3 is a horizontal sectional view taken onthelineB-ofFigureh Figure 4 is a horizontal sectional view taken on the line 4-4 of Figure 1;

' Figure 5 is a horizontal sectional view taken on the line 5--5 of Figure l;

Figure 6 is an enlarged fragmentary topplan view of the dome section of the combustion chamber with parts broken away;

Figure 'I is a sectional view taken on the line 1-1 of Figure 6;

(Cl. 12B-m99) Figure 8 is a sectional. view taken on the line 8 8 of Figure 5. y Referring now to the drawings, A is the ash pit, B is the combustion chamber, C is the radiator, and D is the outer casing of a warm air furnace embodying our invention. As shown, the ash pit A has suitable upright walls i and a. horizontally disposed frame 2 provided with a suitable closure y3. 'I'he combustion chamber B is preferably formed of relatively light gauge sheet 10 steel andpreferably comprises three sections 4,' 5 and 6, respectively. The lower section 4 comprises the fire box portion of the combustion chamber. and preferably rests upon a ring 'l welded to the upright walls l of the ash pit at the top thereof. The intermediate section 5 is substantially frusto-conical in conguration 'and is welded in overlapping relation to the lower -section 4 at the top thereof. The upper section 6 comprises the dome portion of the combustion chamber and is-welded in overlapping relation to the intermediate section 5 at the top thereof. The radiator C preferably encircles the dome section 6- of the combustion chamber and is sup- .ported thereon by suitable brackets 8. Preferably this radiator C isv connected to the dome section 6 by a flue 9 and is provided at diametricallyl opposite points with a clean-out passage I0 having a suitable closure Il and a smoke outlet or ue passage I2. Casing D is conventional in 30 form and encloses the ash pit A, combustion chamber Band radiator C. As usual, the casing D has suitable openings for receiving the ash pit frame 2, re box passage I3. and clean-out and ue passages l0' and I2, respectively, and is pro- 35 vided at the top with warm air ducts I4. -The grates i5 at the bottom of the combustion cham-I ber and the shaker mechanism'li preferably correspond to the structure set forth in our application filed October 22,:1934, bearing Serial No. 40 749,440 and form no part of the present invention.

In the present instance the lower and inter-v mediate sections 4 and -and the upright walls of the dome section 6 of the combustion chamber are formed from flat substantially rectangularshaped light gauge sheet metal plates of uniform length. Preferably such plates are crimped by a die (not shown) so that they will have the corrugated formation shown. One of said corrugated plates is bent to form the circular lower section 4 and opposite ends thereof are arranged in overlapping relation and welded together to complete the formation of said section. Another of said plates is bent to form the frusta-conical intermediate section 5, it being understood, of

course, that the corrugations at the top of said section are pressed closer together to obtain the contracted upper end thereof and the frusto-conical form.' The`overlapping ends of said second sheet are welded together to complete the formation. The remaining corrugated plate is bent to circular form and its corrugations are uniformly pressed closer together from top tobottom to form the upright walls of the dome section 8. 'Ihe concavo-convex top Il' of'the dome section is formed'separately and is placed upon and welded to inturned portions IB' of the upright walls of said dome section as illustrated in Figures6 and 7 of the accompanying drawings. Thus, it is apparent that the corrugated formavtion of the plates permits them to be bent into various shapes. In fact, the nnished sections l. 6 `and l need not' be circular as shown. They could be square or some other suitable configuration if desired.

After being separately formed, the sections 4, i andi are welded together in superposed relation as .illustrated in Figures 1 and 2 of the drawings. Preferably the lower section I rests on'the ring l between a flange Il thereof and f ber below the frusto-conical section 5 to aid combustion of fuelin the fire box portion of the chamber. Thus, the air is preheated by the flre brick lining I l before it enters the lire box portion ofthe combustion chamber.

From the foreoing it will be apparent that we have provided a simple but very emcient furnace construction. The corrugated structure provides practically double the heating area in direct contact with the fire and obviates the use of fins and similar means heretofore employed for obtaining increased heating or radiating surfaces.

vLighter gauge metal is used and the manufacture and assembly of separate ilns have been dispensed with entirely, hence the combustion chamber is less expensive to make than heretofore. Regardless of the diameter of the sections I, and 6, the heating area per unit of height of all of said sections is constant. Thus, the heating area per unit of height in a given horizontal plane at the top of the combustion chamber is 'the same as at the bottom. In fact, it has been found that the radiator C may be smaller due to the greater heating surface of the combustion chamber.

In use the combustion chamber may be installed in either a coal or. gas furnace. It could' `be used as a heating element in a hot water heat- 5 er. In all uses, the corrugated structure adds to the rigidity permitting strength with lighter gauge metal. It permits the passagel of air upwardly beside the fire brick lining IB so as to be preheated before entering the` fire box portion of 10 Y the combustion chamber. It permits the formation of the frusto-conical section such as! of the the flre box portion I of said chamber. while the smaller end of the intermediate section yis in communication with the flue outlet I2.

What we claim as our invention is:

1. A furnace combustion chamber having two cylindrical portions of different diameter formed from two sheets of the same: length, and an intermediate portion -joining the two cylindrical portions, the external area per unit of height of all of said portions being constant. y

2. A furnace combustion chamber having a tapered portion, the larger end thereof being in communication with a source of heated gases, and the smaller end thereof being in communication with a flue outlet, the external area per unit of height' of said portion being constant. 40

3. A furnace combustion chamber having upper and lower substantially cylindrical portions of different diameter, and an intermediate frusto conical portion tapering upwardly from the lower portion to said upper portion, each of said porg5 tions having substantially vertically extending corrugations. the corrugations of the upper portion being narrower than the corrugations of the l lower portion, and the corrugations of the intermediate frusto conical portion varying in width from the lower to the upper portions and merg- 'ing with the respective corrugations thereof.

4. A furnace combustion chamber having two substantially cylindrical portions of different diameter formed from two sheets of the same length, the external area per unit of height of said portions being constant.

EARNEST L. WATSON. MARGARET E. WATSON. 

